As a welding shop, we know that rust proofing a car is an important but often overlooked step in vehicle maintenance.
From experience, we know: the cars that are prone for rust, where it usually starts and- very importantly- how it can be prevented.
So in this article today we’re going to share the best ways we know to prevent rust on your car and stop it from spreading as- although we do love welding- we get sick and tired of condemning otherwise mechanically sound cars to an early grave because of the “iron worm”.
Although we do provide a car rust proofing service in our workshop, if you're on a budget or just prefer to do it yourself here are a few tried and tested methods to keep the rot at bay.
Take a look at these six simple things you can do to fight the rust on your car- and win.
1) Find the Rot before it Spreads- Checking your Car for Rust
First things first, find the rot that’s already on your car. Rust on the underside of a car is normal and, unless you’ve just bought a brand-new vehicle, you’ll be very lucky to have a one without a single spot of corrosion on it.
When checking your car for rust, start with the underneath, sills and arches. This is the most common place for corrosion to start on a vehicle because it’s the area that gets the most stick from water, salt, mud and debris off the road.
Ideally you should get the car power washed off so you can get the best possible view of your bodywork and steam clean it too if that’s possible. If not you’ll just have to try and wash the underside of the car off as best you can then, once it’s dry (it’s best to do this on a warm, dry day) take a wire brush to scrape off any lingering mud.
Jack up the car (using axel stands for safety) so you can properly look underneath and use an old flat headed screwdriver to poke around at anything that looks suspiciously crusty.
Next, check under the bonnet in the engine bay as well as around the doors, window seals and boot lid (the bottom of the front windscreen on vans is a usual hot spot for corrosion). These are the next most likely places to find rust as a common area for two seams of metal to overlap, as well as being a trap for rainwater.
Finally, and only if you’re really committed to rust-busting your car, take your interior carpets out to have a look underneath there. You’d be surprised how often we find that a car has rotted from the inside out- particularly cars with soft tops and sunroofs that have a tendency to leak.
If you do find any corrosion on your car you need to act fast to stop it from spreading.
And if you’re tempted to leave the rust on your car alone trust us- fixing the small problems quickly is better than sitting on it a while and allowing them to develop into bigger problems. You need to treat that rust immediately and aggressively.
So how do you treat it? There’s a few different ways to stop the rust spreading on your car.
What's the Best Way to Remove Rust on a Car? Three Options...
1) If the rust is on a panel that you can easily replace, like a door or front wing, then simply removing the rotten old panel and fitting another one is often the best option. Instead of messing around trying to repair a badly rotted panel we always advise customers to buy a good replacement one if that’s going to work out cheaper for them. Most of the time we’d choose clean, rust-free second hand panels over repro ones.
Why's that? Well, although admittedly reproduction panels for cars vary widely in quality between brands, in general they tend to be made from lighter-weight metal than original parts which makes them not as hard wearing, and they often don’t fit as well as original panels- but just go for whatever you can get your hands on and your budget allows.
2) Welding repairs are the second-best option if fully replacing the panel isn’t going to work for you.
This involves fully chopping out all the rotten sections, fabricating (or purchasing panels) and fitting fresh, clean metal.
Welding in new sections to replace rot works just as well as unbolting and replacing the panels but can be expensive or difficult and time consuming to do yourself if you’re not an experienced welder.
3) The last and least effective option by far is grinding back the rust and using treatments.
This almost always delays the rust development rather than getting rid of the problem altogether. Kurust and other similar style treatments are available but will only be able to do so much once the rot has set in.
If this is your only option, grind back the rust spot on your car until you get to clean metal (assuming there is some clean metal to find!) treat it with a rust-killer treatment then prime and paint it. Don’t make the common mistake of just grinding off the rust and touching it in with paint because it will quickly reappear.
If you don’t find any rust on your car, well- lucky you! But that doesn’t mean corrosion won’t develop in the future.
Check over your car regularly for spots and bubbling developing in the paintwork. Pay particular attention to the sills and arches which, as we mentioned before, are the most common places. You need a keen eye and to know exactly what you’re looking for as the bubbling in the paintwork will be very faint at first and get progressively worse over time.
2) Waxoyl the Underneath, Inside Doors and Engine Bay
Once you’ve assessed the rust situation and dealt with any problems it's time for the rustproofing treatment- you need to cover your car in a protective layer of waxoyl.
Waxoyl is probably the best know and widely available product for preventing rust on your car and it’s what we use in the workshop (but there are other options out there if you want to do your own research.)
The best way to apply it is with a waxoyl gun hooked up to a compressor that allows you to spray into all the little cracks. Spray your rustproofing treatment on all the bodywork underneath including brake pipes, brake hose ferals and shockers just NOT THE BRAKES AND EXHAUST. Also wear a mask and do it in a well-ventilated area as the fumes are strong.
The main place rust develops, other than underneath, is on the seam where two panels overlap so that’s where you want to be focusing on the rest of the bodywork after you've completed the underside.
Take the trim panels off your doors and get a good coat in the bottom where water can sit as well as under your interior carpets if you want to do a proper job of it. On older vehicles it’s more important to do the window mechanisms as they tend to be less well sealed and water gets in more easily.
If you don’t have a compressor and spray gun just do your best with a paintbrush and pot.
The one thing you do not want to do is give your car a pathetically light misting with one of those rubbish spray cans of waxoyl. The nozzle blocks up, that is not enough waxoyl to do anything significant and you’ll most likely be on for days getting nowhere- so don’t waste your money.
Depending what application method you’re using, a 5 litre can of waxoyl will be sufficient to do an averaged size car inside and out the first time you do it and then you want to be keeping on top of the underside using about a litre and a half at least once a year as it will wash off over time.
3) Keep Your Car Clean
Once you've got rid of the existing rot and applied your protective coat of Waxoyl the number one thing you can do to stop your car rusting is keep it clean.
Wash it at least once a month and more often in bad weather when the roads are muddy.
Focus on the underside- the arches and sills again, where it gets the most dirt. Ideally use a power washer to blast off all the dirt underneath. If you don’t own a power washer (or even a drive) there’s self-service car washers available to use which aren’t that expensive, or just go for the bucket and sponge option.
Polish it at least once every six months. This isn’t just about making your car look pretty- polish contains wax that forms a protective layer over the paintwork to deflect water and stop rust getting in.
Undertrays are also good for keeping the underside and engine bay clean, but over time they can get broken and fall off (true story- a well-meaning and very concerned guy once flagged me down on the motorway in an absolute panic to tell me I had something hanging off the bottom of my car- it was my undertray!)
And, I know it sounds stupid, but try to avoid driving through loads of mud when you can- that’s not always possible so just make sure to drive through mud and water slowly to avoid flicking it up under the car.
4) Keep your Car Dry in a Garage or Use a Car Cover
Water is rust's best friend so you need to try and keep your car as dry as possible- not an easy task when you live in the rainy UK!
As we mentioned earlier, allowing water to sit on your car will rot it out- a particular problem for open flat bed trucks as well as boot lids and door sills. So keep nooks and crannies dry and check that drain holes- usually found in doors, sills and under the bonnet- haven’t become blocked. Clean these out with a pipe cleaner if they have been blocked.
Also clean up any spills inside your car immediately and consider having rubber car mats rather than the carpet ones.
The best thing to do to keep your car dry is to keep it garaged when you’re not using it (although be warned that heated garages can speed up the rusting process if there’s already rot on your car) but I realise that’s not an option for everyone, so you should also consider a car cover.
What's the Best Car Cover for Outdoor Use in the UK?
Car covers get a lot of bad press, especially from classic car owners, as they have a reputation for rubbing against the paintwork in windy weather and causing scratches as well as condensation in hot weather, heating up and stripping off the paint on your car(!!) to which we’d say are very fair points. But our experience of them has been good so as long as you buy one that:
If you find a car cover that covers all these points it should help protect your car from the worst weather Britain has to offer.
Of course the most important thing is to make sure you don’t leave your vehicle parked on grass all the time.
5) Avoid Stone Chips and Other Damage to the Paintwork
Another thing that’s pretty hard to avoid is getting stone chips on your car which are sort of inevitable no matter how careful a driver you are- but here are a few tips for it anyway.
Drive slower on motorways and drive really slow, like 20mph slow, on freshly gravelled roads (you’d think this would be obvious but when a road near us was done recently the amount of nearly new cars we saw going flat out down it was ridiculous).
Also don’t follow too close to other cars on the road (not only is this a dickish thing to do anyway, you risk getting stones flicked up at you).
And try to avoid gritting lorries, or at least give them a wide berth on the motorway.
The more realistic thing you can do to prevent stone chips is to invest in a bonnet bra, wheel arch plastic protective covers and mud-flaps which are all excellent for deflecting debris kicked up off the road and protecting your paintwork.
6) Consider a Vehicle Wrap or Ceramic Coating
This last one is for the big spenders out there. A vehicle wrap relies on the car being rust-free to start with and can really only be done by a professional detailer, at least if you want it to look good, so you could be looking at a four-figure sum to get that done- but it is one of the most effective ways to rustproof your car and protect your paintwork.
Ceramic coatings are a relatively new technology that could take over from car wraps in the future- again they need to be done by a professional as they involve a lot of prep work and the right conditions to apply the layers of coating so you won’t be saving money, they’re just another option that’s out there.
These are both extreme measures but are durable and long lasting so if you’re planning to keep your car for the foreseeable future or want to protect a classic or luxury car this is definitely an option to consider.
So there's our six simple ways to stop rust from developing and spreading on your car.
The three main steps are:
For even more protection from rust:
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